Definition of accentual-syllabic

prosody

: characterized by lines with a fixed number of stressed and unstressed syllables

Finally, Sidney is presented as the first English poet who was a master of strict accentual-syllabic meter and yet able to vary this meter with a deliberate, controlled, and often gorgeous counterpoint of speech rhythms.

—Robert Lowell, Collected Prose, 1987

Accentual-syllabic verse is built up of pairs or triads of syllables, alternating or otherwise grouping stressed and unstressed ones. Syllables usually keep their word accent, or the accent they would have in phrases in normal speech.